Imagine you’re aboard a commercial jet as it waits in the queue for takeoff. You look out the window and see a car pull up behind a passenger jet that’s already on the runway. Not just any car, but a rare 1970 Plymouth Superbird.

The Superbird was a homologation special, built in limited numbers to qualify it as a “production” car with the sole purpose being to dominate NASCAR. It had an aerodynamic, wedge-shaped nose that allowed it to hit 200 mph around tracks like Daytona and Talladega. A ridiculously tall wing provided downforce and stability and kept the car from going airborne, which is exactly what the jet in front of it is about to do.

The pilot pushes the throttles forward, sending 14,000 pounds of thrust rearward from each Pratt & Whitney JT8D turbofan engine. The driver of the Superbird grits his teeth, white knuckles clenching the wheel while the car shakes violently, and mashes the throttle pedal to the floor as the jet surges forward. The Plymouth gives chase, hanging close all the way to 100 mph. After about 20 seconds, the plane pulls away. Once it reaches 150 mph, the big 737 lifts off into the sky. The Superbird brakes, then turns around to do it all again.

As crazy as that scenario sounds—especially in the safety-at-all-costs context of today—it really did happen. Not as some daredevil movie stunt, but as an officially sanctioned government test program. The most incongruous part of the story is that this 440-cubic-inch-engined, hydrocarbon-spewing performance car was owned and operated by none other than the Environmental Protection Agency. It has been restored to its original government-service condition and will go up for auction this weekend. First, though, we take a look at the car’s history and where it has been for the last four decades.

An Unlikely Program

Soon after its formation in late 1970, the EPA was tasked with finding the leading causes of environmental air pollution. There was plenty of speculation as to the source or sources, but data needed to be collected to test the various theories. For example, was car exhaust or exhaust from airliners more to blame for poor air quality? Some thought the heavy metals in wear particles from bias-ply tires and asbestos brake dust were contributing to the problem. The EPA needed to find out what constituted the greatest threat to public health and do it in a cost-effective way.

John Moran was the EPA section chief in North Carolina at the time and the person who conceived the Plymouth Superbird project. We spoke to Moran, who has since retired, to get the inside story.

After wrapping his head around the vast amount of data that needed to be collected, Moran recalled, he realized that designing individual lab tests would cost a small fortune. Simply putting a jet engine in a test cell to collect exhaust samples could have cost well into six figures.

Moran reasoned that it would be cheaper and more accurate to collect the air samples in the field. To do this, the EPA would need a car that was capable of following a jet on takeoff. Chrysler had already done extensive wind-tunnel testing of the Superbird and the positive results—the aforementioned top speed and high-speed stability—made it the logical choice. Moran wrote up the proposal and sent it to the purchasing department. Legendary NASCAR builder Ray Nichels won the contract with the low bid of $25,000 to acquire and prep the car—when new, the Superbird’s base price was $4298.

Nichels located a white 1970 Plymouth Superbird with the 440 Super Commando engine and a four-barrel carb. He modified the car for high-speed runs—including swapping out its original automatic transmission for a heavy-duty four-speed manual—using his vast experience as the preferred car builder for Chrysler’s factory-supported teams. In an attempt to make the Superbird less race-car-like, Nichels left its vinyl roof intact and painted the car in a sensible blue. John Moran picked up the car from Nichels Engineering’s shop in Griffith, Indiana, in May of 1972. We reported the seminal event in our September 1972 issue.

The car was driven from Indiana to the National Environmental Research Center at Research Triangle Park, North Carolina, and testing began at local airports. Rather than hire a driver, Moran took full responsibility for driving the jet-chasing car. He said no one was sure what was going to happen, and he didn’t want to risk anyone else’s life finding out.

Getting the Lead Out

To get an idea of the forces involved, we contacted Thomas Benson, an expert at the Inlet and Nozzle Branch test facilities of the NASA Glenn Research Center in Cleveland, Ohio. Benson estimates that, as measured from the car 100 feet behind the plane (200 feet aft of the engines) the blast from the engines would be in the 200-to-300-mph range, and the temperature a toasty 150 degrees Fahrenheit. We weren’t able to locate the footage the EPA took from the passenger seat, but there are several videos online showing the effect of jet blast on vehicles. The Superbird, fortunately, was indeed a wise choice for the task.

Much like Colonel John Paul Stapp—the man who risked his life in rocket-sled experiments for the sake of scientific inquiry into the effects of acceleration and deceleration on the human body—John Moran is a true American hero. By identifying lead particulates as a major health threat facing the nation, his work prompted the phasing out of lead in gasoline. Lead was an inexpensive way to improve octane levels, but the health threat—it can affect the brain and nervous-system development—ultimately outweighed the benefit. While unleaded gas and the first fuel crisis may have helped kill muscle cars like the Superbird, efficiency gains have since allowed big-power performance cars to once again roam American streets.

Epilogue

After testing was completed, the EPA’s Superbird was parked at a government lot among old forklifts and filing cabinets. It was broomed in a 1979 government auction of surplus equipment, where it was unceremoniously listed as a “1970 Plymouth car.” Wilbur Walker, a high-school auto-shop teacher trolling the auction for interesting bargains, immediately recognized the car as something special, bid on it, and took the car home for a mere $500. It became Walker’s prized possession and was lovingly cared for during the next 20 years. He repainted the car white, often using it for instructional purposes in his class until his retirement.

Walker’s son sold the car in 2005, allegedly with the proviso that it be restored to its original condition. Brian Chaffee of Everything Muscle in Middlefield, Connecticut, recently finished a three-and-a-half-year restoration and fully documented the car for an anonymous new owner. The docs are complete enough to include original gas receipts signed by John Moran that were left in the glove box.

The EPA’s bird was most recently for sale for the sum of $750,000 or “serious offer”—the restoration reportedly cost $700,000 alone. It’s lot #1778 at this weekend’s Atlantic City Classic Car Show & Auction, and we’ll see what kind of money it brings come Saturday. Given its place in history, we’d prefer to see the historically significant car end up in a museum—maybe a wealthy benefactor will buy it and donate it back to the government for display at the Smithsonian. With any luck, the car’s story will not end here.